Luminescence properties and charge transfer mechanism of host sensitized Ba2CaWO6:Eu3+ phosphor

Eu3+ ions activated Ba2CaWO6 phosphors were synthesized by the conventional high temperature solid-state reaction method. The crystalline nature of the prepared phosphor was identified through XRD analysis and Williamson-Hall plot method. The compositional analysis was carried out by means of EDS. The morphology of the obtained samples were characterized by SEM and TEM analyses. Vibrational modes were studied using FTIR and Raman spectroscopy. It was noticed from the photoluminescence spectra that charge transfer band excitation in the host at 314 nm is much more prominent than the rare earth excitation wavelength at 393 nm to give the dominant 595 nm emission in the host matrix by the energy transfer mechanism. The change in emission intensity corresponding to varying concentration of Eu3+ was studied. The fluorescence lifetime of the samples were calculated. Optical transition intensity parameters and various radiative properties were calculated using the Judd-Ofelt theory. Photoluminescence spectra were used to estimate the CIE chromaticity co-ordinates and were observed to be in the orange-red region. (C) 2017 Elsevier B.V. All rights reserved.